The present inventive concept relates to a method of fabricating a semiconductor device. More particularly, the present inventive concept relates to a method of fabricating a semiconductor device having a dual gate.
Generally, a gate of a semiconductor device, namely a transistor, includes a gate insulation layer disposed on a semiconductor substrate and a gate electrode disposed on the gate insulation layer. The gate insulation layer is usually a silicon oxide layer, and the gate electrode is usually a poly-silicon layer. However, the materials of the components of the gate affect the operating speed of the device, and there is always a demand for semiconductor devices which are smaller and operate at higher speeds. With such considerations in mind, a semiconductor device has been developed in which the gate insulation layer is made of a high-k material, and the gate electrode is made of a metal.